Method of threading wires in muffles and apparatus for practicing same



ACTICING SAME 1961 De 29, 1964 J. R. GUINGAND usmon OF THREADING wmss IN MUFFLES AND APPARATUS FOR PR Filed June 20 United States Patent M 3,163,407 METHOD OF TfHZEADlNG WIRE 1N MUFFLES AND APPARATUS FGR PRACTlCiNG SAD/E Jean Raymond Guingand, Paris, France, assignor, by ntesne assignments, to Societe Anonyrne i-ieurtey, Paris, France Filed June 20, 1961, Ser. No. 118,416 Claims priority, application France, June 30, 136%), 831,565, Patent 1,269,268 8 Claims. (ill. 2653) The invention relates to methods and apparatus for threading wires in muflles.

More particularly, the invention relates to furnaces equipped with muffies and designed for treating'wire.

The furnaces may provide a heat treatment process or a metallization process in which the wires to be treated are received in tubular mufiles the diameter of which is very small in relation to their length. The furnaces are intended for operation in continuous fashion, however, a threading problem arises periodically each time work is resumed or after a wire breaks accidentally.

The threading method commonly employed is a manual one and consists, generally, in using several men at once to push the wire as fast as possible by hand until it emerges at the downstream end of the tube. This is a laborious method requiring personnel for the purpose; it is furthermore unreliable in the case of tubes'exceeding a certain length and becomes entirely inapplicable where excessively long installations are involved.

It may even be said that the development of installations of great length (which would permit h gh-speed treatment) has been restricted by the impossibility of threading wires therethrough, since, in such furnaces, the wire soon heats up and softens on being introduced, then buckles under the thrusting force exerted, finally creating a an obturation.

With a view to overcoming such drawbacks, the invention has for one of its objects a' method whereby the threading of a wire through a muf le is accomplished by high speed mechanical propulsion, this speed being greatly in excess of the normal rate of travel of the wire in the course of treatment and being such that the wire has virtually no time to heat up other than superficially, the core of the wire retaining the mechanical properties needed to ensure stiffness.

The invention further has for its object apparatus for practicing such a method, and, in a preferred embodiment of such apparatus, high speed propulsion of the wire is accomplished by means of a pair of clamping rollers which are movable relative to each other to enable wire engagement to take place, said rollers being associated to at least one motor and to means for synchronizing their motion.

In the case of a furnace comprising a plurality of tubular mutlies, the assembly consisting of the propelling rollers and their driving and synchronizing means is mounted in the form of a mobile and retractable mechanism, together with locking means whereby said mechanism may be clamped in position opposite a given tubular muflie, the retractability feature enabling the positioning to be accomplished without interferingwith the neigh bouring mufliesa The description which follows with reference to'the accompanying drawing, given by way of example only and not of limitation, will give a clear understanding of how the invention may be performed.

In the drawing,

. 1 is a front elevation of the wire threading device. 2 is a side elevation of the device of FIG. 1. 3 is-a plan View of the device of FIG. 1.

BJEbBAh? Patented Dec. 29, 1954 FIG. 4 is an edgewise view of the threading rollers of the device showing their synchronizing gears, and

PKG. 5 is a partial schematic perspective view of a heat treatment furnace with a cut away portion showing the rnufiles. FIG. 5 is on a reduced scale when compared with FIGS. 1-4.

Onto the front face 1 of a heat treatment furnace 1a open tubes 2a are arranged in single or multiple rows with front openings 2, and there is secured to this face a supporting frame 3 which surrounds the front openings of said tubes. The tubes in extend through a heat treatment zone in the furnace la; Said frame 3 has two reinforcing parallel stays 4 and 5 which extend perpendicular to the plane of the frame. These stays are joined together, on the one hand, by a round shaft 6 at the top and are joined, on the other hand, to a square shaft 8 having cylindrical end trunnions, said square shaft 8 being rotatable by means of a stud 9 rigidly connected to each of its ends, each such stud being designed to cooperate with a tubular manipulating rod.

The cylindrical shaft 6 is fixed between the stays 4 and 5. Protective casing it? is coupled to shaft 6 so as to be pivotable thereabout while being slidable along shaft 6 coupled to the outer face of easing it) is a lever arm 11 supporting on its end a counterweight 12. Said casing encloses an upper grooved roller 14 mounted on a shaft 13, adjacent which is arranged a large-module geaiwheel 15. Shaft 13 is the drive shaft of a compressed ah motor 16 the casing of which is fixed to the side of casing lthand compressed air motor 16 is equipped with a cock 17 which is connected to'a flexible supply lead 18. a

A cylindrical rod 1% is located beneath the shaft 6 and is slidable in bearings in the stays 4 andS, one of these hearings comprising a spring-loaded ball type lock Zil designed to cooperate with grooves 21 on said rod 19 and spaced at intervals equal to those separating the tubes 2. Said rod 19 is provided with an operating handle.

assembly being mounted loosely on a shaft 26 passing through casing 23.

The forward portion of casing 23 comprises, at a level corresponding to a plane approximately tangential to said roller 24, a bracket 23a on which are mounted two guiding rollers 27 which are freely rotatable about their respective axes. The bottom of casing 23 is designed to cooperate with a positioning strip 28 rigidly connected to the square shafts, and strip 28 cooperates at its extremities with limit stops 29 and 30 provided at the vertical ends of the stays 4 and 5 as best seen; in FIG. 2. V The device described hereinabove functions in the following manner: a V The bottom casing can'be moved whenin the lowered position shown by the chain-dotted lines in FIG. 2, to a 7 position opposite one of the'tu-bes 2 through which the wire is to be threaded. The bottom casing 23 is moved by a transverse sliding motion underneath the, loom of wires running through the adjacent tubes 2 so asnot to interfere with the passage of the wires through the adjacent tu-bes. When the bottom casing is opposite the tube through which the wire is to be threaded, movement is stopped and transverse motion is prevented by the springloaded ball 2% as it drops into the corresponding groove 21 of shaft 19. The casing 23 is then raised by swivelling the strip 23. Having thus been lifted by the strip 23, the

, casing 23 is retained against the stop 3%). With the casing alignment with casing 23 and then pivoted downwardly to assume the position shown in solid lines in FIG. 2. In the latter position,.the roller 14 clamps the wire against the roller 24 and the gearwheels '15 and 25 mesh together.

The cock 17 is then opened and the wire is driven through the tube 2, preferably with uniform acceleration,

particularly in cases involving the heat treatment of a metal wire, although the invention is by no means limited thereto.

The compressed air-motor 16-prevents any sudden increases in the speed of the wire, any slip between the rollers 14. and 25 and the wire; and any danger of the auxiliary Wire being tightened about its bobbin. The threading operation is accomplished at high speed, e.g., in an installation 50 metres (164 feet) long threading is completed at an average speed of about 150- metres (492 feet) per minute. At such a speed heating up of the auxiliary wire in a tube 2 can onlyaffect thewire superficially, so that its mechanical characteristics, insofaras its resistance to buckling is concerned, remain virtually unimpaired.

The threading operation 'havingthus been accomplished. easily and without any personnel other than a single operator, the end of the auxiliary wire can be joined to. the wire to be treated. The threading mecha-,

nism can then be :opened and retracted sideways, after which drawing of the wire to be treated through tube 2 can be performed'by any conventional means.

It should be noted that both the: retracting and the moving-into-position operations of the threading mechav nism is performed clear of the loom of Wires being treated in tubes 2.

The large-rnodule gearwheels 15 and 25 are-but a convenient means of synchronizing therollers and avoiding buckling due to'ditferences in speed from oneroller to another. Alternatively, an individual motor could be provided for each roller. Similarly, the compressed-air. motor could be replaced by a motor of any type :whatsoever, for instance an electricmotor, certain motors of this type being capable of driving the system at uniformly accelerated speed.

In place of the counterweight 12, elastic, means such as springs could be used for clamping the rollers together.-

ment zone at a predetermined speed, the step of initially,

threading one of said wires, comprising mechanically engaging said one wire at an end thereof in selective fashion while avoiding the other wires, passing saidone wire through said zone independently of the other wires at a speed greatly exceeding that of the other wires so that said one wire leaves said treatment zone with substantially unimpaired mechanical properties and reducingthe speed of passage of said one wire through said treatment zone to that of the other Wires when the one wire extends through said treatment zone.

2. Apparatus for threading a wire through a heated treatment zone, the apparatus comprising means defining said treatmentzone, said rneans being provided with a plurality of openings equally spaced along-a line to permit passage of a plurality of said wires through said zone, means selectively movable to each of said openings in a manner avoiding the other of'the openings whereby the latter said means can be movedpastopenings through which wires are passing while avoiding said wires, said latter means being engageable with one of'said wires in driving relation, means for driving .said latter; means in accelerating fashion and at a speed sufiicient to cause passage of said wire through said treatment zone so that mechanical strength properties of said one wire are sub-' stantially unafliected by passage through-said treatment zone,a pair of parallel shafts, each being on either side of said line of openings, and meansfor supporting one of said shafts from said means defining said-treatment zone for movement along the line of said opening in lookable intervals corresponding to the spacing of said openmgs. I

3. Apparatus as claimed in claim 2, wherein said means engageable with said wire includes a pair of rollers, each being supported for pivotal movement'by one of said shafts.

4. Apparatus as claimed in claim 3 wherein the means for driving the rollers includes means synchronizing the drive thereof, and a motor operatively coupled to one of the rollers in driving-relation.

5. Apparatus as claimed in claim. 3 comprising means coupled to each of said rollers for causing pivotal movement thereofabout the corresponding shaft'between positions corresponding to engaged and disengaged positions.-

for said wire.

6. Apparatus as claimed in claim 4 wherein the means synchronizingthe drive of the rollers includes a pair of gearwheels, each being rigidly coupled to one of saidrollers and in meshing engagement with the other gearwheel with the rollers in position corresponding to said engaged position.

7. Apparatus as claimed in claim 2 wherein said means for supporting said one shaft includes'retractable stops for releasablylocking the one shaft in positions corresponding to the openings.

8. A process as claimed in claim 1 wherein saidpassing of said one wire through said treatment zone is made by applying a substantially constant acceleration to said one wire.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A PROCESS FOR SIMULTANEOUSLY TREATING A PLURALITY OF WIRES BY CONCURRENTLY PASSING THE WIRES THROUGH A TREATMENT ZONE AT A PREDETERMINED SPEED, THE STEP OF INITIALLY THREADING ONE OF SAID WIRES, COMPRISING MECHANICALLY ENGAGING SAID ONE WIRE AT AN END THEREOF IN SELECTIVE FASHION WHILE AVOIDING THE OTHER WIRES, PASSING SAID ONE WIRE THROUGH SAID ZONE INDEPENDENTLY OF THE OTHER WIRES AT A SPEED GREATLY EXCEEDING THAT OF THE OTHER WIRES SO THAT SAID ONE WIRE LEAVES SAID TREATMENT ZONE WITH SUBSTANTIALLY UNIMPAIRED MECHANICAL PROPERTIES AND REDUCING THE SPEED OF PASSAGE OF SAID ONE WIRE THROUGH SAID TREATMENT ZONE TO THAT OF THE OTHER WIRES WHEN THE ONE WIRE EXTENDS THROUGH SAID TREATMENT ZONE. 